Compressor



June 11,1940, c. w. 'METZGAR 2,204,31

' I couramssan l Filed June 4, 193a INVENTOR HIS A TTORNEY.

Patented June "11, 1940 m orrics COMPRESSOR Chester W. Metzgar, Easton, Pa., asslgnor to Ingerscll-Rand Company, Jersey City, N.- J., a corporation of New Jersey Application June 4, 1938, Serial No. 211,735 4 Claims. (01. 230-296) This invention relates to compressors-and more particularly to compressors employed for compressing gases which, because of their objectionable effects, are preferably excluded from the 5 atmosphere;

Of these, chlorine gas is a well known example. This gas, moreover, has a deleterious efiect upon oil lubricants and it is, therefore, essential that it be excludedimm all portions of the compressor depending upon oil for lubrication, otherwise the oil will become solidified and destroy the packing members serving to seal the various chambers of the compressor. It is accordingly an object of the present invention to prevent the exposure of voil lubricated surfaces to the gas pumped by the,compressor.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanying this specification,

and in which similar reference numeralsrefer to similar parts, Figure 1 is a longitudinal view, partly in section, of a compressor constructed in accordance with the practice of the invention, and

25 Figure 2 is a transverse view taken through Figure 1 on the line 2-2.

Referring more particularly to the drawing,

designates the cylinder of a compressor having a compression chamber 2| containing a reciprocatory piston 22. The gas intended to be compressed by the piston 22 is conveyed to an inlet chamber 23 in the cylinder by a conduit 24 and the admission of gas into the compression chamber 2| is controlled by an inlet valve 25 seated in the wall of the cylinder. t

A discharge valve 26, also arranged in the wall of the cylinder 20, controls the fiow of compressed gas from the compression chamber 2| into a dlschargechamber 21 in the cvlinder, whence'the gas may be conveyed to a desired destination by a discharge pipe 28. The piston 22 is provided with the usual rod 29 which extendsthrough a cylinder head 38 and the end wall 3| 0! a crankcase- 32 where said rod may be connected to a crosshead (not shown).

Between the cylinder 20 and the crank case .32 is a sealed distance piece 34 the interior of which, in accordance with the practice ofthe invention, is separated into two compartments or chambers :5 and as by a wall :1. One end of the distance .piece 34 is suitably welded to the wall 3| and the opposite end t0-a ring 33 which lies in the I end of the distance piece and is secured to the head 30 by bolts 39. Bolts 33 also secure thewail u tothe crank case :2, and manholes 40, with covers 6|, are provided for the chambers 35 and 35 to permit access to the bolts 39.

' In view of the adverse effect of chlorine gas on oil lubricant the material relied upon for effecting a seal between the head 30 and the rod 29 is 5 preferably of the self-lubricating type, as for example rings or segments 42 of graphitic material. The rings 42 may, as shown, be arranged in groups of two in metallic holdersv 43 disposed in a bore 44 in the head 30. Theholders 43 are 10 pressed in position by a gland, 45 inserted in the outer end of the bore 44 and secured to the head 30 by bolts 46.

To the end that the holders. 43 may be removed as a unit, rather than separately, bolts 41 are extended through the gland and the holdersand threadedly connected to the innermost holder 43. Thus, whenever it.is desired to remove the packing elements from the bore 44 it is merely necessary to free the gland 45 and the assembly may then be withdrawn from the bore 44' by force appliedto the gland. I 1

In order that the major portion of the fluid medium leaking along the shaft 29 from the compression chamber 2| may be intercepted, and 25 thereby prevented from passing into the chamber 35, an annular passage 48 is formed in an intermediate-holder 43, and a passage 49 opening into the passage '48 extends through certain of the holders 43 and the gland 45 and opens into a 30 conduit, 50 which may be suitably connected to from the compression ch'amber 2| beyond the annular groove 48 may enter, and in the wall of the chamber 35 is a conduit 5| which may also be connected to the inlet side of the compressor or to a suitable pump. (not shown) for evacuating so the chamber 35.

Packing means of the nature inserted in the head 30 are also disposed in the wall 31 to effect a seal about the rod 23 and between the chambers 35 and 36. In the present instance, however, the 45 a sealing rings or segments designated 52 are arranged in a single holder 53' disposed on the wall 31 and secured thereto by clamps 54 and bolts '55. v

A gland 55 forms a closure-'ror the bore 51 containing the sealing members 52 and is secured to 50 the holder 53 by bolts 53.

Inasmuch as the portion of the rod 29 which reciprocates through the wall 3| is exposed to the oil lubricant in the crank case 32' the packing material serving to effects seal between the crank 55 case and the chamber 36 is of the compressible type shown as a series of packing rings 59 arranged in a holder 60 in the wall 3| and secured thereto by a clamp plate 6i and bolts 82. A gland 63 threaded into the holder 60 serves to compress the packing rings 58.

In order to prevent the spreading of oil along the rod 29 to a point where it may be carried into the packing rings 52 a deflector or stop member 54 is attached to the rod. The deflector intercepts such quantities of oil as may creep along the rod in the direction of the wall 31 and deflects it toward the bottom of the chamber 36. The deflector 64 consists of a pair of plates and 66 which are secured together by bolts 81. The plate 35 performs the deflecting function and the plate 66 serves more particularly as a hub for the plate 55 and contains a set screw 88 which is forced against the rod 29 to hold the deflector securely on the rod.

Although the various packing devices provided between the compression chamber and the chamber 36 greatly reduce the chance of exposing the oiled portion of the rod to the gas pumped by the compressor it has been found that the need of attentions to the packing members lying in the head30 and between the chambers 35 and 35 may be further minimized by maintaining a volume of any compressed gas other than that being pumped, as for example dry air, in the chamber 36 of a pressure value in excess of that existing in the chamber 35. The chamber 36 is accordingly provided with a conduit 69 which may lead from a source (not shown) of gas or dry air of requisite pressure value wherewith the chambe 36 is in constant communication.

In the operation of the device and in a struc- I ture having the bleed-oil channels including the groove 68 and associated passages the major portion of gas leaking along the rod 29 will be intercepted by these channels and conveyed to a point where it may again be reintroduced into the compressor. Any gas, however, that flows beyond the annular groove 48 and through the gland 45 will enter the receiver 35 whence it may escape or be withdrawn through the conduit 5|.

By maintaining dry air in the chamber 36 at a pressure in excess of the pressure in the chamber 35 such gas as may be present in the latter chamber will be prevented from flowing along the rod into the chamber 36. By thus excluding the gas from the chamber 36 the oil on the rod will retain its lubricating qualities and the oiled surface of the rod and the packing device in the wall 3| will remain undamaged indefinitely.

I claim:

1. A compressor, comprising a casing having a compression chamber and a pressure .chamber, a piston in the compression chamber, a rod for the piston extending through the pressure chamber,

a self-lubricating packing at one end of the pressure chamber for the rod, an oil lubricated packing at the other end of the pressure chamber,

means on the rod to prevent the flow of oil along the rod from the oil" lubricated packing to the self-lubricating packing, and means for constant- 1y introducing pressure fluid into the pressure chamber to prevent fluid medium being pumped by the compressor from entering the pressure chamber.

2. A compressor, comprising a casing having a compression chamber and a sealed pressure chamber and a sealed receiver between the chemhers to receive fluid medium leaking from the compression chamber, an outlet for the receiver, a piston in the compression chamber, a rod for the piston extending through the receiver and the pressure chamber, and means for constantly introducing pressure fluid into the pressure chamber and at a pressure in excess of the pressure in the receiver to prevent the leakage of fluid 'medium from the receiver into the pressure chamber.

3. A compressor, comprising a casing having a compression chamber and a sealed pressure chamber and a sealed received between the chambers to receive fluid medium leaking from the compression chamber, an outlet for the receiver, a piston in the compression chamben a rod for the piston extending through the receiver and the pressure chamber, a self-lubricating packing for the rod at one end of the pressure chamber, an oil lubricated packing for the 5 rod at the other end of the pressure chamber, means on the rod for preventing the flow of oil along the rod to the'self-lubricating packing, and means for constantly introducing pressure fluid into the pressure chamber and at a pressure in excess of the pressure in the receiver to prevent the leakage of fluid medium from. the receiver to the pressure chamber.

4. A compressor, comprising a casing having a compression chamber, a sealed receiver, a sealed pressure chamber and a crank case arranged in the same longitudinal plane in the order set forth, an outlet in the receiver for the escape of gas leaking from the compression chamber, a piston in the compression chamber, a rod for the piston extending through the receiver and the pressure chamber into the crank case, self-lubricating packings for the rod between the compression chamber and the receiver and between the receiver and the pressure chamber, an oil-lubricated packing for the rod between the pressure chamber and the crank case, a' baflle in the pressure chamber secured to the rod to prevent oil flowing along the rod to the packing between the pressure chamber and the receiver, and a conduit for introducing an aeriiorm fluid other than that handled by the compressor into the pressure chamber and at a pressure value in excess of that in the receiver to prevent leakage of fluid medium from the receiver to the pressure chamber.

CHESTER W. METZGAR. 

